The discovery of brain recognition sites specific for benzodiazepines opened the field for identifying specific brain mechanisms mediating anxiety. Rodent and primate models of anxiety were applied to the analysis of the anxiety-producing properties of a series of Beta-carboline compounds previously shown to bind with high affinity to the brain benzodiazepine site. Sensitivity and specificity of the pharmacologically-induced "anxiety" response was investigated. In the conflict test, rhesus monkeys showed a significant decrease in punished and non-punished responding at doses of Beta-CCE as low as 50 ug/kg. In the learned helplessness model, rats treated with FG-7142 developed an inability to learn an escape task twenty-four hours later, equivalent to the long-lasting effects of inescapable tailshock. These results suggest that the "active antagonists" of the brain benzodiazepine receptor induce a response which may be interpretable as stress-induced anxiety.